Observation window for a gas confining chamber

ABSTRACT

An observation window particularly suited for use in visually observing an internal portion of a casing adapted to confine therewithin a fluid medium. The window is characterized by a body having an internal chamber disposed in direct communication with the internal portions of the casing, a transparent closure of a substantially planar configuration, and a heater coil within which the body is confined, whereby gas delivered from the casing to the chamber is heated by the coil for thus establishing within the chamber a cell of unsaturated gas isolating the transparent closure from the fluid medium.

United States Patent Low et al.

[54] OBSERVATION WINDOW FOR A GAS CONFINING CHAMBER [72] Inventors: George M. Low, Acting Administrator of the National Aeronautics and Space Administration with respect to an invention of; James R. Baughman, 7110 Pomelo Drive, Canoga Park, Calif. 91304; Robert Spies, 16980 Cotter Place, Encino, Calif. 91316; Lance G. Hays, 2737 Ridge Pine, La Crescenta, Calif. 91214 Filed: Dec. 21, 1970 Appl. No.: 99,903

[52] US. Cl. ..137/559, 52/171, 219/203,

219/522 [51] Int. Cl ..F16k 37/00 [58] Field of Search ..52/171, 172; 219/203, 522,

[451 Oct. 10, 1972 [56] References Cited UNITED STATES PATENTS 3,527,249 9/1970 Verheyden et al. ..137/559 Primary Examiner-Henry T. Klinksiek Attorney-John R. Manning et al.

[5 7] ABSTRACT 2 Claims, 3 Drawing Figures 33 I /a R0 RR eg if ms PATENTEDnm 10 m2 3 .696, 8 33 JAMES R. BAUGHMAN ROBERT SP/ES LANCE 6. HA VS uvvavroes OBSERVATION WINDOW FOR GAS CONFINING CHAMBER BACKGROUND OF THE INVENTION 1. Field of the Invention The invention relates to observation windows and more particularly to an improved observation window for casings confining therewithin fluid mediums.

2. Description of the Prior Art Frequently, it is desirable to visually observe and/or photograph the contents of a sealed casing, particularly a casing of atype employed in conducting streams of a fluid medium, such as saturated steam. Heretofore, it has been common practice to provide a wall of such casings with openings having seated therein transparent closure members forming hermetically sealed windows. However, where the fluid medium includes a saturated vapor, such as saturated steam, condensation frequently occurs in the vicinity of the closure member. Consequently, due to the affinity of the resulting condensate for the relatively cool surfaces of the closure member, visual inspection of the contents of the casing through the transparent closure member is impeded. This particularly is true where a casing houses a steam turbine and streams of condensate and vapor are caused to impinge on the inner surfaces of the transparent closure members.

Consequently, there currently exists a need for a practical observation window for use in observing the interior portions of casings confining therewithin flow mediums in a fluid state.

OBJECTS AND SUMMARY OF THE INVENTION It is therefore an object of the instant invention to provide an improved observation window for use in observing a portion of the interior of a casing confining therewithin a fluid medium.

Another object is to provide an improved observation window for use in examining a body of fluid having a chamber confining therewithin a cell of unsaturated gas.

Another object is to provide an improved observation window for viewing internal portions of a chamber confining therewithin a saturated gas.

Another object is to provide an observation window for use in inspecting a portion of the interior of a casing including a tubular body confining therewithin a cell of tion window provided with an elongated body terminating in a pair of coaxially related transparent openings, one of said openings being mounted in direct communication with the internal portion of an hermetically sealed, fluid confining casing, while the opposite opening is hermetically sealed by a transparent closure member, an an electrically energizable heating coil associated with the body for establishing therewithin a cell of unsaturated gas isolating the transparent closure member from the contents of the casing.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side elevation of a casing having mounted thereon an observation window which embodies the principles of the instant invention.

FIG. 2 is a fragmented, cross-sectional view of the window, taken generally along line 2-2 of FIG. 1.

FIG. 3 is a fragmentary end view of the observation window shown in FIGS. 1 and 2, pictorially illustrating a result achieved when employing the window.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the drawing wherein like reference characters designate like or corresponding parts throughout the several views, there is shown in FIG. 1 an observation window 10 which embodies the principles of the instant invention. As illustrated, the observation window 10 is mounted on an elongated cylindrical wall 11 forming a casing, not designated, which serves to house a steam turbine. Of course, as will hereinafter become more readily apparent, the window 10 is not limited to uses related to an employment of steam turbines.

The window 10, as best illustrated in FIG. 2, includes a tubular body 12, of a suitable length, formed of any good heat conducting material such as aluminum and the like. One end portion of the tubular body 12 serves as a base portion 13 and is circumscribed by an integral collar 14, which can, if desired, be welded to the body for purposes of coupling the collar and the body into a unitary structure.

The internal surfaces of the body 14 define therewith a cylindrical chamber 15 hermetically sealed by a transparent closure member 16, preferably of a planar configuration, seated across the distal end portion 17 of the body 12. It is to be understood that the closure member 16 serves an an eyepieces and is sealed to the body 12 in any suitable manner, including a use of snap rings, gaskets and the like, not shown, which effectively establish an hermetic seal between the closure member and the body 12. As can readily be appreciated, the particular environment in which the window operatively is employed serves, in part, to dictate the manner in which the closure member is sealed to the body. Since the seal can be established employing various techniques, well within the skill of the art, a detailed description of the mounting of the closure member 16 is omitted in the interest of brevity.

The body 12, through the collar 14, rigidly is coupled to a base plate 18. The base plate 18, is, in turn, seated in an opening 19 formed in the wall 11 and is provided with a curvature such that it readily mates with the wall. A plurality of screw-threaded studs 20 are extended through the collar and are threaded into screwthreaded openings formed within the plate 18 relative to the wall 11. Thus, the plate serves to support the body 12 in an operative disposition.

As best illustrated in FIG. 2, the plate 18 preferably is provided with an opening forming a bore 22 which receives therewithin the adjacent end portion 24 of the base portion 13. As a practical matter, the bore 22 is provided with an annular relief forming a shoulder 26 which receives therewithin the end portion-24 of the body 12. Consequently, the bore 22 serves as an uninterrupted passageway by which the internal portion of the casing defined by the wall 11 is afforded access to the chamber 15, through the plate 18.

In order to enhance seating of the base plate 18, the wall 11 also is relieved to provide an appropriately formed shoulder 28 circumscribing the opening for the base plate 18. Similarly, the base plate 18 is provided with a relief forming a shoulder 30 which mates with the shoulder 28, as best illustrated in FIG. 2. A plurality of screw-threaded studs 32 are extended through the base plate 18 and threadingly are received within suitably formed screw-threaded openings in the wall 11.

Preferably, the plate 18 isformed from a transparent, synthetic plastic material, such as an acrylic, which accommodates passage of light into the chamber for thereby enhancing observation and photographic examination of the contents of the casing with which the window is associated.

Where the window 10 is incorporated in a wall of a casing confining therewithin a flow medium in its fluid state, such as is often found in steam turbines, the medium frequently is a saturated vapor and, as such, includes light-obstructing condensate which is permitted to pass through the bore 22 into the interior of the body 12. In order to convert the saturated vapor into a cell of unsaturated gas, for thereby eliminating condensate, an electrically energizable heater coil 34 is wound about the body 12 and is employed for heating the contents of the body by delivering heat through the wall thereof.

Preferably, the coil 34 is of a type commonly known as a resistance heater. Hence, the coil 34 operatively is coupled with a suitable voltage source 36 adapted to be employed for energizing the heating coil 34. Since electrically energizable resistance heaters are notoriously old, a detailed description of the coil 34 is omitted in the interest of brevity. However, it is to be understood that the temperature of the coil 34 rapidly is elevated, as an electrical current is passed therethrough from the voltage source 36, and that as a consequence an exchange of heat is initiated along the surface of the chamber 15.

In practice, a housing 40, also of a tubular configuration, concentrically is related to the coil 34, as well as the body 12, and serves as a protective cover for the coil. The housing 40 is formed of a suitable insulating material, such as a ceramic material, which functions to impede heat transfer at its outermost surface.

It is intended that liquid contained within fluid passed through the bore 22 into the internal portions of the body 12 to vaporized, through a transfer of heat thereto from the coil 34 so that a cell of unsaturated gas is established within the body 12. Since a vapor, such as a water vapor, tends to be transparent visual observation of the contents of the casing established by the wall 11 is enhanced.

OPERATION It is believed that in view of the foregoing description, the operation of the device will be readily understood and it will be briefly reviewed at this point.

With the observation window assembled in the manner heretofore described, a fluid medium, such as saturated steam is delivered to the casing defined by the wall 11. As the fluid medium approaches the bore 22 it is permitted to pass therethrough into the chamber 15 of the body 12 carrying with it particlesof condensate. The coil 34 is energized through the application of a voltage, acquired from the voltage source 36, for purposes of elevating the temperature of the coil, whereupon heat is transferred from the coil 34 through the wall of the body 12 and exchanged with the medium confined within the chamber 15, through radiation as well as convection. As the medium thus is heated a cell of unsaturated gas is established within the chamber 15. This cell normally tends to be transparent, consequently the medium confined within the casing is isolated from the transparent closure member 16 so that passage of light through the member 16 is enhanced. Hence, visual, as well as a photographic, ex amination of the contents of the casing readily is facilitated.

In instances where the base plate 18 is fabricated from a transparent material, visual observation of the contents of the chamber defined by the wall 11 further is enhanced due to an inherent passage of diffused light through the base plate 18, whereby the interior of the casing is illuminated.

As best illustrated in FIG. 3, where the window 10 is seated in a wall 11 which defines a casing housing a steam turbine, water droplets, not designated, are ejected from the trailing portion of turbine blades, also not designated, readily are observed. Due to the fact that the body 12 confines within its chamber 15 a cell of unsaturated gas, these water droplets are rendered readily discernible and a study of the effects of the steam thus is accommodated.

Of course, as readily can be appreciated, while the window 10 particularly is suited for use in examining the flow of steam through steam turbines, the window also can be employed equally well with numerous environments wherein there exists a tendency for condensate to collect along a surface of a transparent observation window.

In view of the foregoing, it is to be understood that the herein disclosedembodiment of the instant invention provides a practical solution for overcoming the effects of condensate normally encountered in visually and photographically observing effects of mediums confined within sealed chambers, and further tends to eliminate distortion often introduced through the use invention, which is not to be limited to the illustrative details disclosed. What is claimed is:

5 6 1. An observation window for use with an observatherewithin;and tion opening formed within a wall of a casing confining D. means including an electrically energizable heata heated vapor comprising:

A. an elongated body including means defining therewithin an elongated chamber having a pair of 5 coaxially related openings; B. mounting means supporting one opening of said pair in a substantially concentric relationship with an optic axis passing through the observation ing unit of a cylindrical configuration mounted in concentric relation with said tubular body and electrically coupled with a source of voltage for elevating the temperature of the body, whereby vapor confined within the chamber is heated and particles of condensate borne thereby are vaporized. ggf g i g z zg garag Sisal 1:2 :22: m 2. The observation window of claim 1 wherein said modated, mounting means includes a transparent plate seated C. a transparent closure disk hermetically sealing the within the opening formed within Said wall of said other opening of said pair of openings, whereby heated vapor delivered to said chamber is confined 

1. An observation window for use with an observation opening formed within a wall of a casing confining a heated vapor comprising: A. an elongated body including means defining therewithin an elongated chamber having a pair of coaxially related openings; B. mounting means supporting one opening of said pair in a substantially concentric relationship with an optic axis passing through the observation opening, whereby delivery of heated vapor from said casing to said elongated chamber is accommodated; C. a transparent closure disk hermetically sealing the other opening of said pair of openings, whereby heated vapor delivered to said chamber is confined therewithin; and D. means including an electrically energizable heating unit of a cylindrical configuration mounted in concentric relation with said tubular body and electrically coupled with a source of voltage for elevating the temperature of the body, whereby vapor confined within the chamber is heated and particles of condensate borne thereby are vaporized.
 2. The observation window of claim 1 wherein said mounting means includes a transparent plate seated within the opening formed within said wall of said casing. 